Across clinical guidelines, there is consensus that ER, PR, and HER2 testing are central for early breast cancer (EBC) risk assessment, with IHC and confirmatory in situ hybridization (ISH) used to classify tumors as luminal, HER2-positive, or TNBC [293,294,295,296,297,298,299]. This evidence concerns the gene ERBB2 and breast carcinoma.